The present invention relates generally to devices requiring an adhesive in a groove, and, more particularly, to a submount and method of mounting optoelectronics devices.
Optical systems have become increasingly important in modern telecommunications primarily due to their huge information handling capacity. Such systems include lasers, photodetectors, modulators, and other components. The components are usually mounted on a submount. The submount typically comprises a silicon substrate with bonding pads for the components formed on a major surface, and V-shaped grooves etched into the substrate to accommodate optical fibers coupled to the components. The fiber may be secured in the groove by epoxy.
Problems often arise when filling the V-grooves with epoxy. For example, the groove may include a fulcrum portion for fiber alignment, in which case it is difficult for the epoxy to flow and fill the groove. (See, eg, U.S. patent application of Freund and Geary case 73-21, filed Aug. 29, 2002, and assigned to the present assignee.) On the other hand, the grooves may include a well portion at the end nearest the component which desirably should be free from epoxy, and, consequently, an excess amount of epoxy would be detrimental.
For these and other reasons, it is desirable to provide an optoelectronic device with a submount and method which results in a precise amount of epoxy or other material in the V-grooves of the submount.
The present invention, in accordance with one aspect, is a device including a submount and a cover. The submount includes a substrate with a groove formed in the substrate. The substrate further includes at least one cavity formed in the substrate displaced from, but in sufficiently close proximity to the groove so that a controlled amount of adhesive in the cavity wicks into the groove when the cover is placed over the cavity and groove.
In accordance with a further aspect, the invention is a method of fabricating a device comprising providing a substrate including a groove, and at least one cavity formed in the substrate displaced from, but in close proximity to the groove. A controlled amount of adhesive is deposited in the cavity. A cover is then placed over at least a portion of the groove and cavity so as to wick at least a portion of the adhesive from the cavity into the groove.
It is to be understood that both the foregoing general description and the following detailed description are exemplary, but are not restrictive, of the invention.